偶氮染料微生物降解的研究进展

本文评述偶氮染料生物降解研究的新进展,包括:分子结构与其可生物降解性的关系;细菌细胞的透性对偶氮染料还原的限制作用;偶氮还原酶在偶氮双键断裂中的作用;氧气对偶氮染料还原的抑制作用以及中间产物芳香胺的进一步降解,最后指出利用生物工程技术净化印染废水的前景。      

藻菌系统对偶氮染料降解作用的研究

研究了藻菌系统对偶氮染料降解的可能性,机理和环境条件的影响,49种不同类型的偶氮染料降解试验表明,藻菌对染料有较好的降解作用.发现藻类也能直接参与染料的降解,动摇了藻类在稳定塘有机物降解过程中仅能为好氧菌供氧的传统观念.根据典型染料实验研究表明,该系统降解偶氮染料的机理是:染料先被藻菌降解成芳香胺.尔后芳香胺在有氧条件下进一步降解成无机物;在无氧条件下,芳香胺降解受阻。环境条件试验表明,在相当广的pH值、温度、光强和碳源营养水平条件下,该系统仍有较高的降解效果。      

偶氮染料生物降解机理的研究

运用紫外光谱、液相色谱与质谱研究了偶氮染料的降解过程.通过紫外光谱分析,以酸性红B为底物测定了偶氮还原酶的酶活.以甲基红为底物,分析了偶氮染料的降解机理.提出并验证了在偶氮染料还原过程中,存在一个加氢的中间体.     

细菌对偶氮染料的降解及偶氮还原酶的研究进展

综述了目前降解偶氮染料的细菌以及偶氮还原酶的研究进展。探讨了可能的降解机理和相关基因工程菌的开发。     

污泥细菌偶氮呼吸机制与偶氮染料降解矿化机理

利用污泥细菌生物降解矿化偶氮染料,已成功用于偶氮染料废水处理,并将成为该领域研究开发的热点和发展趋势。综述了好氧、厌氧细菌的两种偶氮呼吸机制,并总结了偶氮呼吸直接产物芳香胺类在好氧、厌氧条件下进一步降解与矿化机理的异同,同时提出在偶氮染料废水处理中厌氧-好氧串联式生物反应器能有效用于偶氮化合物的降解矿化。     

链霉菌FX645对偶氮染料红AR30的降解机制研究

从印染厂污泥中筛选到1株对偶氮染料红30(AR30)具有较强脱色降解作用的菌株Streptomyces sp.FX645.通过降解产物的紫外-可见吸收光谱、LC-MS分析及各降解产物在发酵体系中浓度随时间变化的规律,探讨了菌株FX645对AR30的可能降解途径,首先在偶氮还原酶的作用下AR30发生偶氮键的裂解,生成4-硝基-2,6-二氯苯胺与2-[(4-胺苯基)-(2-氰乙基)-氨基]乙酸乙酯,然后分别发生硝基还原、氨基酰化、氰基水解作用,生成一系列的苯胺类化合物.     

环境生物学

Zn污染。用模拟湖水对沉积物进行溶出实验,上清液金属含量符合国家地表水质量标准。成组生物检验(B attery Test)结果表明,三个沉积物样品对无脊椎动物和发光菌均无急性毒性,但对光合藻类的生长有抑制作用。初步用毒性鉴定和评价方案进行的研究结果表明,抑制作用主要由阳离子类型污染物引起。图1表3参9X 179‘101349藻菌系统降解偶氮染料的机理研究/刘厚田…(中国环境科学研究院)刀环境科学学报/中科院环委会一1993,13(3)一332一338环情X一9 研究了藻、菌及藻菌共存系统对偶氮染料降解的机理。so种偶氮染料的降解试验表明,多数偶氮染料可…     

电Fenton法降解甲基橙的机理研究

本文采用紫外—可见光谱和高效液相色谱对电Fenton法降解模拟偶氮染料甲基橙的降解过程及其机理进行了试验研究,结果表明:电Fenton法降解甲基橙存在偶氮式降解和醌式降解两个复杂的降解历程,甲基橙偶氮基团的未成对电子先与反应体相中的·OH结合,分解为多种芳香类物质,接着·OH进一步进攻苯环大π键,生成对苯二酚、苯醌等小...     

偶氮染料废水的生物脱色研究进展

对偶氮染料脱色的厌氧以及好氧生物方法进行了综述,内容包含偶氮还原酶的分析、纯化和脱色动力学研究,以及编码偶氮还原酶基因的克隆表达,和表达所得酶与原始酶的活性以及动力学的对比研究方面。     

偶氮染料对斜生栅藻的毒性作用及结构活性相关性研究

为了揭示不同结构染料对水生生态系统的毒性作用,研究９种偶氮类及２种蒽醌类染料对斜生栅藻的生长抑菌作用,并通过剖析毒性一结构之间的相关关系,探讨了偶氮染料的毒作用机理,１１种染产对斜生栅藻的４８ｈＥＣ５０在１．０９－４１．２２ｍｇ．Ｌ＾－１之间,偶氮染料分子中所包含偶氮键的个数及芳香环上取代基的亲水性和电性均影响染料的毒性,进一步证实偶氮染料的毒同理为Ｎ－Ｎ键不宾为一ＮＨ２后,形成Ｎ＋离子活性民生物     

黄曲霉A5p1对偶氮染料的降解特性和降解途径

以黄曲霉菌株A5p1为生物材料,研究其脱色染料的广谱性,并选择偶氮染料直接蓝71（DB71）为模型底物,探讨脱色特性及降解产物.该菌株对15种染料的脱色测试结果表明,染料浓度为100mg/L时脱色效率为61.7%~100%.该菌对偶氮染料DB71具有生物吸附和生物降解的双重作用,在pH值7.0,温度30℃,染料浓度300mg/L,蔗糖为碳源时对DB71 脱色率为100%.酶分析显示葡萄糖氧化酶和锰过氧化物酶参与染料的降解.FTIR、GC-MS和LC-MS分析确定代谢终产物为萘胺、叠氮萘、2-羟基-6-草酰-苯甲酸和1-萘酚.     

Biodegradation of azo dyes by genetically engineered azoreductase

A azoreductase gene with 537 bp was obtained by PCR amplification from Rhodobacter sphaeroides ASI. 1737. The enzyme,with a molecular weight of 18.7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.     

青霉菌(Penicillium sp.)对三种活性染料的吸附和降解

通过14C标记底物的矿化实验发现青霉菌对多聚芳香族化合物有一定降解能力,本研究以3种偶氮和蒽醌型活性染料为作用底物,结果表明,青霉菌G-1 (Penicillium sp.)对染料进行吸附,吸附等温线符合Langmuir模型,最大理论吸附量(Q_max)可达169.5～243.9mg/g干重,被吸附染料最早在第4d完全脱色降解,有菌丝和去除菌丝的培养液中再次加入染料,均可在20～30h内使染料完全脱色降解.     

藻引发水中偶氮染料的光降解

随着染料工业的发展，染料废水污染也日益严重。目前各国学者也找到了很多处理水中有机物、治理染料废水的办法，但大多局限于腐殖质、过渡金属离子等非生命物质对染料溶液的光降解，本文研究了鱼腥藻、小球藻对几种偶氮染料的光降解情况，并探讨了影响藻对染料溶液光降解的因素。结果显示，pH＝3时，藻能引发水中染料产生明显的光降解，提高藻的浓度，增加光强，均能加快染料的光降解。本文可为利用水体生物资源治理染料废水提供借鉴和帮助。     

蒽醌-2-磺酸盐强化电辅助微生物体系对偶氮染料的脱色效果

为了提高微生物对偶氮染料的降解效率,将电辅助引入微生物还原降解过程,对比研究了EAMS（电辅助微生物体系）、ECS（电化学体系）和MS（微生物体系）对偶氮染料活性艳红X-3B的降解效果,并考察了不同摩尔浓度的AQS（蒽醌-2-磺酸盐）对电微生物体系降解染料的强化作用.结果表明:反应24 h时,EAMS对活性艳红X-3B的去除率达到99.8%,比MS（去除率为61.9%）和ECS（去除率为27.1%）二者之和还要大10.8%;EAMS对活性艳红X-3B的降解过程符合一级反应动力学特征.当c（AQS）为0.050 mmol/L时,降解最快,一级动力学常数为1.962 h-1,是未添加AQS（0.2644 h-1）的7.42倍.加入AQS后,体系中电流升高,说明AQS加快了降解过程中电子传递速率.研究显示,AQS的加入实现了电极-远离电极的微生物-染料之间多相反应界面远程电子传递过程,使整个体系的微生物都可以快速发挥作用,达到强化降解偶氮染料.      

Treatment of simulated wastewater containing Reactive Red 195 by zero-valent iron/activated carbon combined with microwave discharge electrodeless lamp/sodium hypochlorite

A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon (ZVI/AC), microwave discharge electrodeless lamp/sodium hypochlorite (MDEL/NaClO) and the combination of ZVI/ACMDEL/ NaClO was conducted. The preliminary results showed the two steps method of ZVI/AC-MDEL/NaClO had much higher degradation e ciency than both single steps. The final color removal percentage was nearly up to 100% and the chemical oxygen demand reduction percentage was up to approximately 82%. The e ects of operational parameters, including initial pH value of simulated wastewater, ZVI/AC ratio and particle size of ZVI were also investigated. In addition, from the discussion of synergistic e ect between ZVI/AC and MEDL/NaClO, we found that in the ZVI/AC-MEDL/NaClO process, ZVI/AC could break the azo bond firstly and then MEDL/NaClO degraded the aromatic amine products e ectively. Reversing the order would reduce the degradation e ciency.     

Comparison of decolorization of reactive microorganisms isolated from various sources

Azo dyes are among the oldest man-made chemicals and they are still widely used in the textile, printing and the food industries.About 10% - 15% of the total dyes used in the industry is released into the environment during the manufacturing and usage. Some dyes and some of their N-substituted aromatic bio-transformation products are toxic and/or carcinogenic and therefore these dyes are considered to beenvironmental pollutants and health hazards. These azo dyes are degraded by physico-chemical and biological methods. Of these, biological methods are considered to be the most economical and efficient. In this work, attempts were made to degrade these dyes aerobically. Theorganisms which were efficient in degrading the following azo dyes-Red RB, Remazol Red, Remazol Blue, Remazol Violet, Remazol Yellow,Golden Yellow, Remazol Orange, Remazol Black- were isolated from three different sources viz., wastewater treatment plant, paper milleffluent treatment plant and tannery was tewater treatment plant. The efficiency of azo dye degradation by mixed cultures from each source wasanalyzed. It was found that mixed cultures from tannery treatment plant worked efficiently in decolorizing Remazol Red, Remazol Orange,Remazol Blue and Remazol Violet, while mixed cultures from the paper mill effluent worked efficiently in decolorizing Red RB, Golden Yellow and Remazol Yellow. The mixed cultures from wastewater treatment plant efficiently decolorized Remazol Black.     

Continuous treatment of azo acid dyes by photo-dependent denitrifying sludge

Simultaneous removals of dye and nitrate by photo-dependent denitrifying sludge(PDDS)have been demonstrated in a continuousflow bench-scale reactor.The best C/N for the degradation of azo dyes by PDDS was 1.5.The specific removal rate of azo dye AB92 decreased with a decrease in hydraulic retention time and increased with a decrease in solids retention time.The degradation rate of TOC decreased with a decrease in hydraulic retention time.AB92,which has nitro and hydroxyl substitutions in non-para positions,was uniquely degraded.During continuous flow treatment experiments using PDDS,complete degradation of azo dyes AB92 and AO20 at influent concentrations of 40mg/L and 30mg/L,respectively,was achieved with an HRT of 16.